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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef WEBKIT_BROWSER_FILEAPI_FILE_STREAM_WRITER_H_ | 5 #include "storage/browser/fileapi/file_stream_writer.h" |
6 #define WEBKIT_BROWSER_FILEAPI_FILE_STREAM_WRITER_H_ | |
7 | |
8 #include "base/basictypes.h" | |
9 #include "net/base/completion_callback.h" | |
10 #include "webkit/browser/storage_browser_export.h" | |
11 | |
12 namespace base { | |
13 class FilePath; | |
14 class TaskRunner; | |
15 } | |
16 | |
17 namespace net { | |
18 class IOBuffer; | |
19 } | |
20 | |
21 namespace storage { | |
22 | |
23 // A generic interface for writing to a file-like object. | |
24 class FileStreamWriter { | |
25 public: | |
26 enum OpenOrCreate { OPEN_EXISTING_FILE, CREATE_NEW_FILE }; | |
27 | |
28 // Creates a writer for the existing file in the path |file_path| starting | |
29 // from |initial_offset|. Uses |task_runner| for async file operations. | |
30 STORAGE_EXPORT static FileStreamWriter* CreateForLocalFile( | |
31 base::TaskRunner* task_runner, | |
32 const base::FilePath& file_path, | |
33 int64 initial_offset, | |
34 OpenOrCreate open_or_create); | |
35 | |
36 // Closes the file. If there's an in-flight operation, it is canceled (i.e., | |
37 // the callback function associated with the operation is not called). | |
38 virtual ~FileStreamWriter() {} | |
39 | |
40 // Writes to the current cursor position asynchronously. | |
41 // | |
42 // Up to buf_len bytes will be written. (In other words, partial | |
43 // writes are allowed.) If the write completed synchronously, it returns | |
44 // the number of bytes written. If the operation could not be performed, it | |
45 // returns an error code. Otherwise, net::ERR_IO_PENDING is returned, and the | |
46 // callback will be run on the thread where Write() was called when the write | |
47 // has completed. | |
48 // | |
49 // This errors out (either synchronously or via callback) with: | |
50 // net::ERR_FILE_NOT_FOUND: When the target file is not found. | |
51 // net::ERR_ACCESS_DENIED: When the target file is a directory or | |
52 // the writer has no permission on the file. | |
53 // net::ERR_FILE_NO_SPACE: When the write will result in out of quota | |
54 // or there is not enough room left on the disk. | |
55 // | |
56 // It is invalid to call Write while there is an in-flight async operation. | |
57 virtual int Write(net::IOBuffer* buf, int buf_len, | |
58 const net::CompletionCallback& callback) = 0; | |
59 | |
60 // Cancels an in-flight async operation. | |
61 // | |
62 // If the cancel is finished synchronously, it returns net::OK. If the | |
63 // cancel could not be performed, it returns an error code. Especially when | |
64 // there is no in-flight operation, net::ERR_UNEXPECTED is returned. | |
65 // Otherwise, net::ERR_IO_PENDING is returned, and the callback will be run on | |
66 // the thread where Cancel() was called when the cancel has completed. It is | |
67 // invalid to call Cancel() more than once on the same async operation. | |
68 // | |
69 // In either case, the callback function passed to the in-flight async | |
70 // operation is dismissed immediately when Cancel() is called, and thus | |
71 // will never be called. | |
72 virtual int Cancel(const net::CompletionCallback& callback) = 0; | |
73 | |
74 // Flushes the data written so far. | |
75 // | |
76 // If the flush finished synchronously, it return net::OK. If the flush could | |
77 // not be performed, it returns an error code. Otherwise, net::ERR_IO_PENDING | |
78 // is returned, and the callback will be run on the thread where Flush() was | |
79 // called when the flush has completed. | |
80 // | |
81 // It is invalid to call Flush while there is an in-flight async operation. | |
82 virtual int Flush(const net::CompletionCallback& callback) = 0; | |
83 }; | |
84 | |
85 } // namespace storage | |
86 | |
87 #endif // WEBKIT_BROWSER_FILEAPI_FILE_STREAM_WRITER_H_ | |
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